Electromagnetic relay



Oct. 28, 1930.

J. ERICKSON ELECTROMAGNETIC RELAY Original Filed Dec. 31, 1919 Patented Oct. 28, 1930 JOHN EBICKSO N, OF CHICAGO, ILLINOIS,

AUTOMATIC ELECTRIC INC, OF CHICAGO, ILLINOIS,

ASSIGN'OR, BY MESNE ASSIGNMENTS, TO

A CORPORATION OF DELAWARE ELECTROMAGNETIC RELAY Original application filed December 31, 1919, Serial No. 348,548, now Patent No. 1,641,256, dated September 8, 1927. Divided and this application filed September 11, 1925. Serial No. 55,688.

My invention relates in general to electromagnetic relays and has for its object the provision of a relay having a variable t1 me constant; and more especially, a relay having a variable time constant whichis adjustable between much wider limits than are the well known types of slow acting relays now in common use. The preferred means used to attain this and other useful objects will be described fully hereinafter, reference being had to the accompanying drawing. It may be further pointed out that this application is a division of a co-pending application Serial No. 348,548, filed December 31, 1919, which7matured into Patent 1,641,256, Sept. 6 192 The drawing shows a relay of my improved type connected for use in combination with a differential relay to hold a circuit open for a certain definite time interval.

The relay 10 is a modified form of the ordinary type used in telephone apparatus,

modified by securing an additional set of springs, 14 and 15, to the armature; and by the provision of a reed 16, secured to the spring 15, carrying an adjustable weight 17. The weight is effective, upon operation of the relay armature, to periodically separate the springs 14 and.15 for a period depending upon the position of the weight upon the reed. The relay 11 is of the difierential type commonly used in telephone work. This relay is so wound and so connected up in an electrical circuit that when only one windin is energized the armature is attracted, an when both windings are energized the armature is retracted.

The purpose of the embodiment of the invention as shown is to produce a prolonged opening of the circuit extending over conductor 20 whenever the relay 10 is energized. The operation is as follows When the clrcuit of relay 10 is closed at contact devices 21 it attracts its armature and closes contact springs 12 and 13. By this operation a circuit is completed through the two windings of the difierential relay 11 in parallel. The circuit for one of the windings, however, includes the contact springs 14 and 15 and is rapidly interrupted by vibrations of the weight 17. When relay 10 is first energized,

therefore, the diiferential relay 11 is unbalanced and is operated to attract its armature and separate contact springs 18 and 19. As soon as the weight 17 has ceased vibrating contact springs 14 and 15 remain closed and the circuit through both its windings being now closed continuously, differential relay 11 will retract its armature and again close con tact springs 18 and 19. Regulation of the time interval of the differential relay is accomplished by adjusting the weight 17 on rod 16, and by regulating the length of stroke of the armature of relay 10.

In adjusting the relays wide adjustments of the time constant is accomplished by re lating the stroke of the relay armature. 'fi ie adjustment of the weight by moving it up and down changes the frequency of the vibrations and while it alters to some extent the duration of a series of vibrations it is of use chiefly in adjusting the frequency to thenatural period of the device which has to be operated.

Having described my invention what I deslre to have secured and protected by Letters Patent will be pointed out in the appended claims.

What is claimed is:

1. In combination, a normally closed circuit, together with means for opening said circuit for a predetermined interval, said means consisting of a differential relay controlling said circuit, another relay energized to close a circuit for said differential relay to operate the same, said other relay having means for subsequently causing the restoration of said differential relay while the other relay remains energized.

2. In combination, a pair of rela s, means for causing the operation of the ii to complete an operating circuit for the second and means on the first relay for preventing the second from remaining operated for more than a predetermined period irrespective of whether the first relay remains operated or not.

3. In a circuit arrangement, a differential relay, a second relay having a pair of normally open contacts and a pair of normally rst relay.

closed contacts, a circuit for one winding of said differential relay including only said normally open contacts, a circuit for the other winding of said differential relay in- 5 cluding both pairs of contacts, an armature on said second relay for closing the normally open contacts upon energization of said second relay and means controlled by the attraction of said armature for periodically opening the normally closed pair of contacts to cause the operation of said difi'erential relay.

4. In combination with a differential relay, a controlling relay having a pair of contacts closed responsive to its energization and having a second pair of contacts intermittently opened for a limited time during its period of energization, and circuit connections between the windings of the difier'ential relay and the contacts of said controlling relay for causing the actuation of the diflerential relay for the period during which the said1 second pair of contacts are being actuate 5. In combination, an electromagnetic device having two windings, circuits for said windings including a branch common to both winding normally open at one point, a relay having contact members for closing the open point in said circuits and other contact members for periodically opening a second point in the circuit of one of said windings, and a weight attached to one of said last contact members for periodically operating them for a definite interval in response to an energization of said relay,

In witness whereof, I hereunto subscribe my name this 9th day of September, 1925.

. JOHN ERICKSON. 

